Amblyopia Management and Risk of Recurrence Binocular...

Amblyopia – Management and Risk of RecurrenceBinocular Vision Anomalies – When is it Appropriate

to Treat Them?Faye Mather – Advanced Orthoptist

Amblyopia

Amblyopia

Stimulus Deprivation

Anisometropic

StrabismicMixed

Meridional

Treatment Options

▪ Conventional occlusion and atropine occlusion –both effective treatments (PEDIG, 2003; PEDIG, 2008a)

▪ Both offered as a first-line treatment at WHH, when appropriate

▪ Conventional occlusion tends to be the most common treatment method

Commencing Treatment

▪ Patient has had a refraction, fundus and media assessment

▪ Full-time glasses wear

▪ A minimum of 1-line IOD

▪ End of refractive adaptation – some exceptions

Ceasing Treatment

▪ Equal VA

▪ No improvement in the amblyopic eye for 3 or more consecutive visits

▪ Reduction of the VA in the non-amblyopic eye

▪ Low density of suppression on the sbisa bar – risk of intractable diplopia

▪ Reports of diplopia in the presence of manifest strabismus

Recurrence of Amblyopia

▪ Recurrence rate 24-27% (PEDIG, 2004; Bhola et al., 2006; Walsh et al., 2009) – defined as a reduction in the VA of 2 or more lines

▪ Associated with better VA in the amblyopic when treatment stopped, level of improvement and previous recurrence

▪ Not associated with age, treatment duration, presence of strabismus or level of stereo

Stereopsis

Stereopsis

▪ First demonstrated at 3-4 months old

▪ Level varies with different tests

Test Child (Seconds of Arc)

Adult (Seconds ofArc)

Randot Circles 64.1 21.3

TNO 109.9 40.5

Frisby 250.7 142.8

(Simons, 1981)

Stereopsis – Normative Values

Age Frisby RandotCircles

TNO TitmusCircles

3 years 250” 70” 120” 200”

4 years 250” 70” 120” 140”

5 years 250” 70” 120” 100”

Adult 250” 20” 30” 40”

(Scott and Mash, 1974; Romano et al., 1975; Simons, 1981)

Reduced/Absent Stereopsis

▪ Reduced VA in one/both eyes

▪ Strabismus – including microtropia

▪ Anomaly of convergence/accommodation

▪ Lack of understanding – due to age/test used

▪ Non-organic cause

Reduced/Absent Stereopsis – Management

▪ Identification of underlying cause

▪ Glasses wear

▪ Amblyopia treatment i.e. conventional occlusion/atropine occlusion

▪ Exercises to treat anomalies of convergence/accommodation – exercises improve NPC/NPA and fusional reserves which may improve stereopsis

Convergence

Convergence

Normal NPC is ≤ 10cm

Symptoms of Convergence Insufficiency

▪ Diplopia

▪ Headaches – frontal

▪ Eye strain

▪ Difficulty reading

▪ Blurred vision

Convergence Insufficiency - Management

▪ Exercises • Effective if conducted properly under supervision

• The patient must have sufficient cooperation and motivation

• The patient should be in good general health

• Various exercises used – smooth pen convergence, dot card, prism bar, stereograms

Convergence Insufficiency - Management

▪ Prisms

• Indicated for patients who are not responding to exercises or are unable to conduct exercises effectively – Fresnel prisms should be trialed before incorporation

• Fresnel prisms may also be used in conjunction with exercises initially if NPC is particularly reduced – aim to wean off prisms

Convergence Insufficiency - Management

▪ Surgery/Botulinum Toxin • Not indicated for primary convergence insufficiency – no

evidence that surgery improves the convergence mechanism

• May be indicated for convergence weakness exophoria when the patient has not responded to exercises

• A prism trial may be indicated first – those who do not respond may have defective motor fusion and may be poor candidates for surgery (Ansons and Davis, 2014)

Convergence – Key Points

▪ Only treat patients who are symptomatic

▪ Refer to Orthoptist for differential diagnosis and management

▪ Refrain from prescribing prisms prior to patients seeing the Orthoptist

References

▪ Pediatric Eye Disease Investigator Group, 2008a. A randomized trial of atropine versus patching for treatment of moderate amblyopia: Follow-up at 10 years of age. Archives of ophthalmology, 126(8), p.1039.

▪ Pediatric Eye Disease Investigator Group, 2003. A comparison of atropine and patching treatments for moderate amblyopia by patient age, cause of amblyopia, depth of amblyopia, and other factors. Ophthalmology, 110(8), pp.1632-1637.

▪ Pediatric Eye Disease Investigator Group, 2008b. Patching vs atropine to treat amblyopia in children aged 7 to 12 years: a randomized trial. Archives of ophthalmology, 126(12), p.1634.

▪ Holmes, J.M., Lazar, E.L., Melia, B.M., Astle, W.F., Dagi, L.R., Donahue, S.P., Frazier, M.G., Hertle, R.W., Repka, M.X., Quinn, G.E. and Weise, K.K., 2011. Effect of age on response to amblyopia treatment in children. Archives of ophthalmology, 129(11), pp.1451-1457.

▪ Walsh, L.A., Hahn, E.K. and LaRoche, G.R., 2009. The method of treatment cessation and recurrence rate of amblyopia. Strabismus, 17(3), pp.107-116.

▪ Bhola, R., Keech, R.V., Kutschke, P., Pfeifer, W. and Scott, W.E., 2006. Recurrence of amblyopia after occlusion therapy. Ophthalmology, 113(11), pp.2097-2100.

▪ Pediatric Eye Disease Investigator Group, 2004. Risk of amblyopia recurrence after cessation of treatment. Journal of American Association for Pediatric Ophthalmology and Strabismus, 8(5), pp.420-428.

▪ Simons, K., 1981. Stereoacuity norms in young children. Archives of Ophthalmology, 99(3), pp.439-445.▪ Scott, W.E. and Mash, J., 1974. Stereoacuity in normal individuals. Annals of Ophthalmology, 6(2), pp.99-101.▪ Romano PE, Romano JA, Puklin JE: Ster- eoacuity development in children with normal binocular single vision. Am J

Ophthalmol 79:966\x=req-\ 971, 1975. ▪ Ansons, A.M. and Davis, H., 2014. Diagnosis and management of ocular motility disorders. Oxford: Wiley Blackwell.

Diplopia – Red Flags Differential diagnosis of recent and

longstanding strabismusSonia MacDiarmid – Head Orthoptist

Aims

▪ Highlight ‘red flags’ for patients presenting with diplopia

▪ Clues from the patient to aid diagnosis

▪ Urgency of referral

Observations

Gait

Dystonia

Limb weakness

Gait

Parkinsonianmovements

TremorNavigational

skills

Abnormal head posture

Orbits/Lids

Facial asymmetry

Taking a Good Case HistoryListen to the patient’s description – let them talk

▪ Onset – gradual/sudden

▪ Direction of the diplopia

▪ Near/distance disparity

▪ When do they notice the diplopia – constant or intermittent? Does it vary? Uhthoff's phenomenon? Fatigue?

▪ Pain – location/nature of pain

▪ Headaches – waking up/bending down/coughing

▪ Monocular or binocular diplopia

▪ Associated signs/symptoms

Signs/Symptoms

Numbness

Pins needles

Neck stiffness

Weakness NauseaWeight

gain/loss

Social history

Drinking/smoking/weight gain

Medication/recreational drugs

Family history

Stress/mental wellbeing

Medical History• Diabetes • HTN• Hyperlipidaemia • Parkinson’s Disease• MS• Thyroid dysfunction • Recent infection/illness• Ocular trauma • Other forms of trauma • Previous ocular

history…decompensating childhood squints/ suppression mask diplopia

Cover Test

Look for Incomitance – children can have incomitant squints

Esotropia larger for distance - VIth, decompensating distance esophoria, myopia with esotropia, accommodative/convergence spasm

Exotropia – IIIrd, (pupil and non pupil sparing) Parkinson’s disease, INO (MS)

Vertical squint - IVth, skew ( supine test) or mechanical, decompensating congenital IVth

Mechanical and supranuclear - small deviations compared with deficit

Variability – Myasthenia gravis

Assessing Eye Movements

Look for

▪ Description of the diplopia

▪ Greatest restrictions/limitations

▪ Ductions and versions

▪ Lid changes

▪ Globe retraction

▪ Variability

▪ Nystagmus

▪ Torsion

▪ Head tilt test

Binocular vision • Convergence deficit – Parkinson’s

• Reduced/absent stereopsis –childhood microtropiadecompensated

• Suppression – mask diplopia or nystagmus

• Extended vertical motor fusion

• Important – guide our treatment options

Differential diagnosis Acquired v Longstanding

Acquired

• History

• Awareness of abnormal head posture

• Incomitance

Longstanding/Congenital

• History

• Unaware of AHP

• Presence of amblyopia/microtropia

• Extended vertical fusion range

• Concomitance

Pupil involvement • Horners – red flag

• IIIrd nerve – No pupil involvement –

diabetic

– Slow progressing pupil involvement

Lid assessment • Blink rate – reduced in PSP and

Parkinson’s

• Evidence of blephrospasm –Parkinson’s, benign, PSP

• Apraxia of lid opening - PSP

• VIIth nerve function

• Ptosis- Horner’s

Red Flags▪ Pupil-involvement – Horner’s

▪ Incomplete III palsy – pupil may be affected later

▪ Pain (IIIrd)

▪ No recovery or improvement within 12-weeks – importance of serial Hess charts, measurements in 9 positions to monitor improvement or progression

▪ Multiple cranial nerve palsies

▪ Variability

▪ Papilloedema

▪ Neurological signs/symptoms…

Urgent radiological Investigation

▪ IIIrd N with pupil involvement and/or pain ▪ Consider for those under 60 years of age ▪ Patients without any appropriate history or

trauma for diagnosis ▪ Multiple CNP▪ Patients without known microvascular risk factors ▪ Recurrent CNP▪ CNP that is not recovering after 12 weeks

Referral pathways to Ophthalmology ▪ Routine – Standard referral route to Ophthalmology primary

care ( current wait – 5 Weeks) ▪ Urgent referrals ▪ Warrington ED▪ WEEP ( Warrington emergency eye provision)

– Min 6 sessions per week Mon-Friday– On call rota shared with STHK– GP urgent referrals via ICE system– Emergency eyes email – All referrals triaged – Aim to see urgent diplopic patients within 24 hours ( orthoptist +

Ophthalmologist

Treatment options • Fresnel prisms – acute phase

(refrain from incorporation in the acute phase)

• Aim to incorporate once stable at least >12 weeks

• Torsion ( IVth ) – barrier to prism, occlusion

• Sector occlusion • Acute VIth nerve – botox injection

to MR urgently

• Botox (horizontal squints only)

• Strabismus surgery – Mr. Bregu

• Monitor for improvement/progression

• Advice – MECC, driving, eye health, support

Recap

▪ Overview of binocular vision

▪ Normative values

▪ Amblyopia treatment overview

▪ Ocular motility

▪ Red flags

▪ Referral process

Thank you

▪ Sonia.macdiarmid@nhs.net

▪ Faye.mather@nhs.net